I wish I would have been able to join some form of martial arts class when I was younger, it always intrigued me. Our family didn't have the funds when I was young, and when I turned 16 I went to work and never looked back. I would do things different if given the opportunity.

I've known numerous people who had black belts in karate, and other martial arts, and most of them were the kind of people I'd expect to lose a fight very quickly, so I'm pretty sceptical about the whole thing.
I'm sure some karate people are genuinely hard, but I think most of them, in a fight, forget their training, and revert to who they were beforehand.

I didn't take lessons but I watched while my son took it and got their black belts. I learn a little from watching. I took one fight class for my job and the boss was surprised how strong I was and how easy it was for me to do it. One can learn a lot from watching.